The Direct Current to Direct Current (DC/DC) power supply can convert input direct current into required direct current. For example, in an AMOLED display, the input DC voltage needs to be converted into three DC output voltages of AVDD, ELVDD and ELVSS by utilizing DC/DC. Power efficiency test is an important test for AMOLED DC/DC. The traditional power efficiency test solution is as follows: under different input voltages and output voltages and different loading conditions, devices such as a multimeter or an oscilloscope are utilized to test the parameters of the input and output voltages and currents of the DC/DC. However, since all the parameters need to be tested at the same time, then multiple devices are required at the same time, and it is also time consuming to acquire test data from multiple devices, thereby leading to a tedious process of the power efficiency test.